Portugal has some pretty cool bridges! First up is the ArrÃ¡bida Bridge over the Douro River in Porto. The bridge is 493 metres long, and at the time of its construction in 1963 it had the largest concrete span of any bridge in the world. If you look closely on the eastern side you can see the curve of the arch underneath the bridge (compare with the image on Wikipedia to see what I mean). Next up is the Ponte 25 de Abril, which crosses the Tagus river in Lisbon. It was originally named Salazar Bridge but after…